This invention relates to a plane speaker.
In comparison with the conventional corn speaker constructed so that a voice coil is disposed at the rear edge part of a corn-shaped diaphragm and actuated by application of magnetic field generated by a cylindrical magnet, the so-called plane speaker constructed so that voice is emitted by a before and behind reciprocal displacement of a flat diaphragm is advantageous in that it is usable for instance as car speaker and the like because its whole thickness can be made compact in the direction of vibration. However, the conventional plane speaker is disadvantageous in that the means for actuating the diaphragm is complicated in construction and consequently the production cost becomes high; localized vibration is caused on the diaphragm so that it becomes difficult to obtain a high quality voice extending through the whole frequency range; and the like.